JPH03116585A - Control system for magnetic recording and reproducing device - Google Patents

Abstract

PURPOSE:To decrease the damages on a magnetic tape by the stop and restart of the recording and reproducing of the device by adding plural meaningless frames to frames recorded with data and synchronizing the recording and reproducing speeds of the data on a magnetic recording and reproducing device side with the recording and reproducing speeds of a computer. CONSTITUTION:Recording is executed on the magnetic tape by adding >=1 meaningless frames to the frames recorded with the data by the instruction from the computer. The meaningless frames are omitted and the data of the frames recorded with the data are transferred via an interface to the computer at the time of reproducing. The host computer can continuously execute the operation of the device either at the time of recording and reproducing in this way. The smooth operation is thus executed without repeating the stop and retransfer of the magnetic tape.

Description

DETAILED DESCRIPTION OF THE INVENTION (Field of Industrial Application) The present invention relates to a control method for a magnetic recording device, and in particular to a rotary head type digital audio recorder (DAT).
) is used to control a magnetic recording device for recording and reproducing data in a computer or the like.

(Prior Art) The storage capacity of hard disks and the like used in computers is increasing year by year. If the data recorded on these devices is lost due to damage to the hard disk, it will take a great deal of time and effort to reconstruct it. Conventionally,
In order to prevent this unexpected situation, a method is used in which the contents of hard disks, etc. are periodically recorded and saved on magnetic tape (this is called a backup).

In this case, as the magnetic tape for recording data, an oven-reel type tape called MT or a small cartridge tape called a streamer has been used. MT has the problem that the tape size is large and the device is also large, while small cartridges have the problem that the data capacity that can be recorded is small, so these devices are not suitable for backup of modern computers. It no longer fits.

On the other hand, in recent years, DAT has been developed, and it has attracted attention because it has a data storage capacity of 1 gigabyte or more in a small cartridge, and attempts are being made to use it for computers.

However, in the case of DAT, since recording and playback is performed using a rotating head, it takes a long time for recording and playback to start up, and if the computer's data transfer is interrupted or cannot be done in time, the operation will stop temporarily. was there. Furthermore, when there is a request for data transfer from the computer again, there is a problem in that smooth data transfer cannot be performed due to the start-up delay of recording and reproduction.

As an invention that attempted to solve this problem, JP-A-63-16
There is a data recorder described in Publication No. 0074.

This data recorder solves the problem of start-up time delays by continuing to record meaningless frames without stopping recording when data from the computer is interrupted.

(Problem to be solved by the invention) The speed at which a computer records data on a data recorder is
Not only does it differ depending on the computer, but the time a computer can receive and receive data during recording and playback also differs depending on its state.

When recording, it was recorded smoothly using meaningless frames, but when playing back, it is not possible to receive and receive data at the same place and at the same timing as when the data was interrupted during recording.

Conventional technology has not been able to absorb such instantaneous changes in computer data transfer speed through recording and playback, and to perform smooth recording and playback not only during recording but also during playback relative to the average data transfer speed. Not considered.

The present invention deals with the time that occurs when a magnetic recording device temporarily stops recording and reproducing data and then starts again when the data transfer speed of a computer is slightly slower than the data transfer speed at which the magnetic recording device records and reproduces data on a magnetic tape. To solve the problem of extremely low execution speed due to delays, to provide a device that can perform smooth recording and playback as a data recording and playback device for computers, and to cause less damage to magnetic tapes due to stopping and restarting recording and playback of the device. An object of the present invention is to provide a highly reliable magnetic recording device.

(Means for Solving the Problems) In order to achieve the above object, the present invention instructs a magnetic recording/reproducing device to the data transfer speed that a computer can perform on average, and adjusts the magnetic recording/reproducing device to match the data transfer speed. By adding a plurality of meaningless frames to frames in which data is recorded by the recording/reproducing device, the data recording/reproducing speed of the magnetic recording/reproducing device is made to match that of the computer.

Furthermore, to distinguish between data frames and meaningless frames, a flag indicating that the frame is a meaningless frame is added to the second recording area within the frame.

Furthermore, when recording and playing back multiple frames at once,
By recording consecutive frame numbers in the second recording area of meaningless frames, it is possible to distinguish between the two.

(Function) At the time of recording, the identification information of the frame in which data is recorded and the meaningless frame is recorded in the second recording area of the frame, so that at the time of reproduction, only the frame in which data is recorded can be taken out based on this information. Furthermore, since the number of meaningless frames to be added is set according to the data transfer speed that the computer can execute, malfunctions will not occur.

(Example) A first embodiment of the present invention will be described below with reference to FIG.

The magnetic recording/reproducing apparatus of this embodiment includes an interface 1,
Command analysis issuing unit 2, command control unit 3, mechanical control unit 4, data formatter 5, extension storage unit 6
, a recording/reproducing section 7, a cylinder 8, a rotary head 9, and a magnetic tape drive section (not shown).

Recording and reproduction on the magnetic tape 10 is performed by diagonally recording tracks using a rotary head 9 attached to a cylinder 8, similar to the DAT.

The rotary head 9 has two recording heads and a total of four reproducing heads alternately attached to the cylinder 8.

Interface 1 is an SCSI (Small Computer) that communicates with a host computer.
System + Interf'ace). This interface is A N S I (A+++
erican natlonal 5 standardf
or Inf'ora+atlon 5ystea+s
) is standardized in X3.131-1986. Through this interface 1, the host computer
Instructs this device to record and play data. The instructions are given by several bytes of data called a command disk libter block (CDB). host computer is SC
The commands given to the device of this embodiment via 8I include:
In addition to recording and reproducing data, there are several types of functions, including setting the operating mode of the device, performing reference and self-diagnosis, and reporting execution results.

The command analysis/issuance unit 2 that received this CDB
Check the command defined in B and analyze whether the command can be executed by this device.

If the command is executable, the command control unit 3
Transfer DB. The command control section 3 causes the mechanical control section 4 to perform a predetermined operation according to the contents of the command. The mechanical control section 4 controls the cylinder 8 and a tape drive mechanism (not shown), winds the magnetic tape 10 around the cylinder 8, and transports it at a constant speed. The data formatter 5 also converts data sent and received via the interface 1 into a recording format, and converts reproduced data into a data format for sending to a host computer.

The data converted into a recording format by the data formatter 5 is converted by the recording/reproducing section 7 into a data pattern to be actually recorded on the magnetic tape.

Conversely, the data read out from the reproduction pattern by the recording/reproducing section 7 is transferred to the data formatter 5.

Next, a case will be described in which the magnetic recording/reproducing apparatus of this embodiment operates as a sequential device, such as when backing up a hard disk of a host computer.

First, an outline of the operation when a data recording command is given to the magnetic recording/reproducing apparatus from the host computer will be explained.

The host computer follows the 5CSI protocol,
Select the device on which data recording should be performed. First, S.C.
Execute the Arbitration phase to declare the use of the 3I bus. Following this, a section phase is executed to select the magnetic recording/reproducing apparatus of this embodiment.

Interface 1 recognizes that it has been selected in the section phase. As a result, the command control section 3 is notified via the command analysis and issuing section 2 that the present magnetic recording/reproducing apparatus has been selected.

The command control unit 3 that receives this signal executes the command phase on the interface 1 via the command analysis and issue unit 2 in order to receive and receive commands from the host computer.

When the host computer recognizes that the command phase has started, it specifies a recording command and recording data length in the CDB and transfers it to the present apparatus.

This CDB is input to the command analysis issuing section 2 via the interface 1. Here, command analysis issuing section 2
checks the command specified in this CDB, and since it is a command that can be executed by this device, transfers it to the command control unit 3.

The command control unit 3 executes a data out phase using the interface 1 in order to receive data of the length specified by the CDB from the host computer according to the recording command. In this phase, the host computer outputs the data read from the hard disk to the SC3I bus.

Interface 1 stores this data in buffer memory 1.
Record in 1.

When receiving data of the length specified by the CDB, the command control unit 3 instructs the data formatter 5 to create a format, and at the same time causes the interface 1 to execute the status phase and message in phase, and sends a message to the host computer. Terminates the recording command.

However, the actual recording operation has not ended. This device is a helical scan type device that uses a rotary head 9 to record diagonally on a magnetic tape, and records while moving the tape at a constant speed. 2~ until recording is possible.
It takes 3 seconds. Therefore, a common method for magnetic tape devices is to temporarily store data in the buffer memory 11 and then record the data all at once (buffer mode).

The data formatter 5 reads the data recorded in the extension storage section 6, and stores the received data in the buffer memory 11 so that the specified transfer speed is achieved.
The data arrangement is converted to a format that can be recorded on magnetic tape, and a number indicating the location of the data to be recorded is set according to the format.

Note that, as will become clear from the description below, the extension storage unit 6 records data such as the number of gap frames that are added when the data transfer speed needs to be changed.

When this is completed, the command control section 3 instructs the mechanical control section 4 to select the recording mode. The mechanical control unit 4 rotates the cylinder 8 at a constant speed of 200 rpm to perform a recording operation, and transports the magnetic tape at a constant speed of 8.13 mm/s. When both of them reach a predetermined speed and are in a stable state, the data formatter 5 sends the data to the recording/reproducing section 7. The recording and reproducing section 7 modulates the data into a data pattern to be recorded on a magnetic tape, and records the data on a recording rotary attached to a cylinder 8 via a rad 9.

Next, an outline of the operation when reproducing data with the apparatus of this embodiment will be explained.

The operations up to the point where this apparatus receives and receives the CDB from the host computer are the same as those described in the recording operation. CD
In B, a reproduction command and reproduction data length are set. Upon receiving this command, the command control section 3 instructs the mechanical control section 4 to select the reproduction mode. As a result, the mechanical control unit 4 rotates the cylinder 8 at a constant speed of 200 rpm and transfers the magnetic tape at a constant speed of 8.13 rpm.

When the constant speed transfer is achieved, the recording/reproducing section 7
It takes in the data output from the tarhead and demodulates the data pattern. The data is transferred to the buffer memory 11 via the data formatter 5. The data formatter 5 that received this data, contrary to the case of recording,
An operation of rearranging data to be transferred to the host computer within the buffer memory 11 is performed.

When this is completed, the command control section 3 causes the interface 1 to execute the data in phase, and transfers the data of the length specified by the CDB from the buffer memory 11 to the host computer. After this, the interface 1 is caused to execute the status phase and message in phase, and the command is terminated.

When the host computer refers to or changes the mode of this device, it uses a mode sense command and a mode select command. This command does not involve tape movement.

The command control unit 3 that has received the mode sense command transfers the mode sense data stored in the command control unit 3 to the host computer in the data-in phase, executes the status phase and message-in phase, and executes the command control unit 3. Terminate execution.

Further, the command control unit 3 that has received the mode select command receives mode data in the data out phase, and executes changes in the specified mode and parameters. The data transfer rate change parameter of this device is recorded in the extension storage unit 6. After receiving the mode data, the command execution ends with the status phase and message in phase.

These commands do not involve magnetic tape movement.

In this device, the format of the DAT recorded on the magnetic tape is as follows.

Figure 2 shows the frame structure. One frame consists of two tracks recorded by two recording rotary heads. These tracks are formed from the bottom to the top of the drawing, respectively, and the recorded signal is 90 degrees in total length, with a margin of 5.051 degrees from the bottom, and a subcode P.
Preamble for LL (phase locked loop) 0.
918 degrees, 1st subcode 3.673 degrees, postamble 0.459 degrees, gap 1.378 degrees, ATF (Au
tomatIe Track Finding) Signal 2.296 degrees, gap 1.378 degrees, data PLL preamble 0.918 degrees, data 58.776 degrees, gap 1,378 degrees, ATF signal 2.296 degrees, gap 1.378 degrees , PLL preamble for subcode 0.
918 degrees, second subcode 3.673 degrees, postamble 0.459 degrees, and margin 5.051 degrees.

The figure represents this schematically and is not to exact scale.

In this device, the data inputted by the recording/reproducing section 7 is
A predetermined error detection/correction code is added to the data section of the book track and arranged. The error detection/correction code added here is the same as that used for music.

In addition, the first subcode and the second subcode each have 2
048-bit data can be recorded, and each sub-code is divided into 64-bit backs, similar to the music recording format. In this device, a group number (described later), which is data position information, is recorded in each pack.

FIG. 3 shows the group format of this embodiment.

One group consists of 32 frames, and the first three frames and the last one frame are treated as gap frames that have no meaning as data. Data to be transferred to the host computer is recorded in each data portion of the 28 frames sandwiched between the gap frames.

The data format of the 28 frames is shown in FIG. As is clear from FIG. 4, in this embodiment, this data section is further divided into 128 bytes of user data, 4736 bytes of system data, and 25464 bytes of error detection/correction code to improve the reliability of the annotator. and manage it.

The first and second subcodes of each frame have an 8-byte back structure as shown in Figure 5, and contain the consecutive frame numbers within the group and the number of groups from the beginning of the magnetic tape. Record the group number indicating the Incidentally, FIG. 5 shows the format of the bag.

The upper 4 bits of the first byte indicate the back item,
In this embodiment, it is set to "0001". The group number is recorded in the second and third bytes, and the frame number is recorded in the fourth byte. The 8th byte is the exclusive OR of the data from the 1st byte to the 7th byte.

In this embodiment, the frame number of the first gap frame is "-31" and is a continuous number that increases by one until the frame number "28" of the last gap frame.

This device uses this group as the basic unit for recording and playback.

That is, in the case of recording, when bytes are stored in the data 128 for one group in the buffer memory 11, the data formatter 5 adds an error detection/correction code and creates back data to be recorded in the subcode. Arrange the data so that it can be recorded frame by frame. Thereafter, the group number of the gap frame and the frame number '-3m are added to the subcode, and the subcode is transferred to the recording/reproducing section 7. Next, while increasing the frame number by 1, the frame number “2” is set.
Transfer up to 8”.

In the case of reproduction, the received group number and frame number are checked, error correction is performed on the data excluding gap frames, and then the user data is transferred to the host computer. Gap frames and data frames are identified by frame numbers.

In the case of the group format of this embodiment, 128 bytes of data are recorded in 32 frames.

One frame is recorded by one rotation of the cylinder 8, and since the cylinder 8 is rotating at a constant speed of 2000 rpm, the recording/reproducing time of one frame is 30 ms. The recording and reproducing time for 32 frames in one group is 960 ms. Since 128 bytes are transferred in this time, the data transfer rate to the host computer is 133 bytes 7 seconds (128 bytes/960 m5).

Therefore, if the host computer transfers data to the 133 byte at a data transfer rate of 7 seconds or more, recording and reproduction can be executed without stopping the magnetic tape.

However, some small computers, such as personal computers, cannot achieve this transfer speed.

When the data transfer rate falls below 133 bytes in 7 seconds, the device must stop transporting the magnetic tape because there is no more data to record or there is no buffer memory to store the read data. - When the magnetic tape is stopped, it takes 2 to 3 seconds to transport the magnetic tape again and apply servo so that the head traces the track correctly. Furthermore, in order to continue recording and reproducing data at the location where data recording and reproducing was interrupted, it is necessary to rewind the magnetic tape, reproduce the interrupted group, and then continue recording and reproducing. Therefore, data transfer with the host computer cannot be performed smoothly.

If the host computer wants to transfer data to and from this device in 100 bytes in 7 seconds, the transfer speed is changed using a mode select command.

However, this change is effective only when a recording operation is performed after the change and is played back. Changing the transfer speed has no meaning for data that has already been recorded.

The command analysis and issuing unit 2 that receives the mode data via the interface 1 reads the transfer rate change parameter set in the mode data, converts it into an additional number of gap frames corresponding to the set value, and converts this into an additional number of gap frames that corresponds to the set value. It is recorded in the storage unit 6. There are two types of gap frames: a bridge gap that is added before a group, and a post gap that is added after a group. The command analysis and issuing unit 2 records the numbers of these two types of gaps to be added in correspondence with the transfer speed in the extension storage unit 6.

The relationship between the data transfer rate T and the number of gap frames X to be added is expressed by the following equation.

T-128000/30 (32+X) However, T:
Transfer rate Kbytes/sec Therefore, the data transfer rate of the host computer is 1
If byte 00 is 7 seconds, 10.7 frames will need to be added. Since the transfer rate for this device needs to be lower than the data transfer rate for the host computer, in this case, 11 frames are added, and the data transfer rate for this device is 99 bytes and 7 seconds.

FIG. 6 shows the processing flow of the recording operation of the data formatter 5 of this embodiment.

The data filer 5 adds 1 to the number of the group recorded immediately before to set the group number of the group to be recorded from now on (step Sl).

Next, data 128 for one group is stored in the buffer memory 11.
It is checked whether a byte is stored in (step S2). If the data stored in the buffer memory 11 is less than 128 bytes (step S2 is negative), the process is terminated and the process waits for data to be sent from the host computer.

If byte data is stored in 128 (step S2 is affirmative), an error detection/correction code is added (step S3).

Next, a group number is set in the subcode pack (step S4).

Thereafter, a frame number is set in the subcode pack according to the format shown in FIG. 3 (step S5
).

Next, data is read from the extension storage unit 6 (step S6), and it is determined whether it is necessary to add a GAP frame (step S7).

If the data in the extension storage unit 6 is “0” (
If step S7 is negative), no GAP frame is added, so the data stored in the buffer memory 11 is output to the recording/reproducing section 7.

In this embodiment, '11' is stored in the extension storage unit 6.
Since ° has been set, step S7 is affirmative, and in order to add 5 frames before the group and 6 frames after the group, the frame numbers of the subcode pack "-82~-4"129''~ “34” total 11
Frames are added before and after the group, respectively (steps 88-511).

Thereafter, the frame with the smallest frame number is output to the recording/reproducing section 7 and recorded on the magnetic tape (step 51).
2).

FIG. 7 shows a group format recorded by the apparatus according to this embodiment. This results in a format in which 43 frames form one group.

FIG. 8 shows a reproduction operation processing flow of the group formatter 5 of this embodiment.

First, the data of the designated group number is read from the recording/reproducing section (step Sl). Next, a pack of subcodes is extracted from the data received from the recording/reproducing section 7, and the process waits until a group number to be reproduced is detected. When a group number to be played back is detected, the frame number of the group is read and it is determined whether it is a negative number or a number larger than '28#, that is, whether the frame number indicates a gap ( Step S2). If the frame number indicates a gap (step S2 is affirmative), the frame is discarded.

In the case of other frames (step S2 is negative), the frames are recorded in the buffer memory 11 according to the frame number (step S3).

After repeating this until reading data for one group (
Step S4 is affirmative), and the error detection/correction code is decoded (Step S5). Correct any errors in the read data.

Output the group number read into the command control unit 3,
The process ends (step S6).

In this way, in this embodiment, a gap frame is added to a group when a transfer rate change is instructed from the host computer, so that the gap frame is added to the group not only when recording data but also when playing back data. There is no need to stop transporting the magnetic tape. This has the effect of making it possible to perform a good data transfer operation.

A second embodiment of the present invention will be explained with reference to FIG.

The figure is the same as FIG. 1 of the first embodiment except for the data formatter 20. The outline of the recording and reproducing operation of this embodiment is also the same as that of the first embodiment. Furthermore, the frame structure and group format are also the same. FIG. 10 shows a subcode pack of this embodiment. 1st byte to 7th byte of pack
The exclusive OR of the byte data is stored in the 8th byte. In addition to the frame number and group number, a gap flag (GF) is assigned to the most significant bit of the fifth byte for the back.

As in the first embodiment, when the host computer changes the transfer rate using a mode select command, the number of gap frames to be added is stored in the extension storage section 6.

Data formatter 2 in recording operation according to this embodiment
The processing flow of 0 is shown in FIG.

The data formatter 20 records the group number to be recorded by adding 1 to the group number recorded immediately before (step Sl). It is checked whether bytes are stored in the data 128 for one group in the buffer memory 11 (step S2), and if there are less than bytes in the data 128 (step S2 is negative), the process is terminated. On the other hand, 12
If byte data is stored in 8 (step S2
is affirmative), an error detection/correction code is added in step S3.
), and sets the group number and frame number in the subcode (steps S4 and S5).

Next, data is read from the extension storage unit 6 (step S6), and it is determined whether a gap frame needs to be added (step S7). If this data is 0'' (step S7 is negative), no gap frame is added.

As in the first embodiment, if the transfer rate of the host computer is 100 bytes and 7 seconds, the gap-frame is 1
Add one frame. Therefore, step S7 becomes affirmative. Assuming that there are five pre-gap frames and six post-gap frames, a frame in which a group number and a gap flag are set is added to the subcode (steps 88 to 511).

This data is output to the recording/reproducing section 7 (step 512
). As a result, the groups shown in FIG. 12 are recorded on the magnetic tape.

The processing flow of the reproduction operation according to this embodiment will be explained with reference to FIG.

The signal input to the recording/reproducing section 7 via the rotary head 9 is demodulated into a digital signal and input to the data formatter 20 (step Sl). The data formatter 20 checks the group number of the subcode and determines whether it is the next group to be read. When the target group number is detected, it is checked whether the gap flag in the subcode is set (step S2), and if it is not set (step S2 is negative), the data is buffered as a data frame according to the frame number in the subcode. It is recorded in the memory 11 (step S3). However, frame numbers "-3" to "-1" and "28" are also considered gap frames.

On the other hand, if the gap flag is set (step S2 is affirmative), the frame is read and discarded.

It is determined whether data for one group has been stored (step S4), and if the data is stored (affirmative in step S4), error detection is performed, and if there is an error, correction is performed (step S5). Thereafter, the command control unit 3 outputs the hegel loop number to notify that the data has been stored in the buffer memory 11 (step S6). The command control unit 3 reads data from the buffer memory 11 and transfers the data to the host computer via the interface 1. As described above, data transfer is performed by simply flagging the added gap frame. The speed can be matched to the transfer speed of the host computer, resulting in optimal data transfer.

In the first and second embodiments, gap frames are provided before and after groups, but it is clear that gap frames may be added only before or after groups. As a result, the recording/reproducing process remains unchanged, and exactly the same effect can be obtained.

A third embodiment of the present invention will be explained with reference to FIG.

The figure is the same as FIG. 1 of the first embodiment except for the data formatter 30. The recording/reproducing operation of the apparatus of this embodiment is the same as that described in the first embodiment. Further, the format of the track recorded on the magnetic tape in this embodiment is the same as that shown in FIG.

In this embodiment, data is recorded for each frame, so
Groups are not formed as in the first and second embodiments. Data transferred from a host computer is recorded or reproduced on a magnetic tape frame by frame. In this case, 1
The data capacity recorded in a frame is the same as a music DAT, and is 5760 bytes. Since this is recorded and played back at 3 Qms, the data transfer speed is 192 to 848.
It will be 7 seconds.

If we add X gap frames to N data frames in order to make this data transfer rate the transfer rate specified by the host computer, the data transfer rate T will be:
The following formula is obtained.

T-(56258N) /30 (N+X)T; Data transfer rate K by 5 seconds Set the data transfer rate of the host computer to 100 to 848
If it is 7 seconds and the data frame is 10 frames, then if the gap frame is 9 frames, it will be 98.7 or 848.
A transfer speed of 7 seconds is obtained.

FIG. 15 shows a subcode pack of this embodiment.

The recording operation by the data formatter 30 of this embodiment will be explained with reference to the processing flow shown in FIG.

The number of data frames 10 is stored in the extension storage unit 6 according to the transfer speed changed by the host computer.
, the number of gap frames 9 is recorded.

When recording is instructed, 1 is added to the most recently recorded frame number.
A value obtained by adding up is set (step Sl). If data for 10 tracks have been recorded in the buffer memory 11 (step S2 is affirmative), a frame number is recorded in the pack to be recorded in the subcode (step S3). Next, data is read from the extension storage unit 6 (step S4), and it is determined whether a gap frame needs to be added (step S5).

In this example, in order to add nine gap frames, a frame with a gap flag set in the subcode pack is added to the data frame (step S6).

This data is output to the recording/reproducing section 7 and recorded on a magnetic tape (step S7).

FIG. 17 shows the data format recorded on the magnetic tape according to this embodiment.

The processing flow of the reproduction operation of the data formatter 30 of this embodiment will be explained with reference to FIG.

The data input to the recording/reproducing section 7 via the rotary head 9 is converted into a digital signal and input to the data formatter 30 (step Sl). The data formatter 30 determines whether or not the gap flag of the subcode is set (step S2), and if the designated frame number is detected (step S2 is negative), records the data in the buffer memory 11 (step S2). 83).

On the other hand, if the gap flag is set in the subcode (step S2 is affirmative), data of this frame is not recorded.

When it is determined that the data for the specified frame has been stored (
(Yes in step S4), the data formatter outputs a frame number to the command control unit 3 every time it reads one frame of data, and transfers the data to the host computer via the interface 1 (step S5).

This is repeated for the number of frames specified by the host computer, the number of read frames is output to the command control section 3, and the process ends.

As described above, even when the group configuration is not used, data transfer matching the data transfer speed of the host computer can be realized, so there is an effect that optimal data transfer can be performed.

(Effects of the Invention) The present invention is realized by adding frames that have no meaning as data in order to match the data transfer speed of the device for recording and reproduction with the data transfer speed of the host computer that uses the device. ing.

Therefore, according to the present invention, the host computer can cause the device to operate continuously during both recording and playback, allowing smooth operation without repeatedly stopping and retransferring the magnetic tape. The present invention can be expected to have the effect of increasing the lifespan of the magnetic tape because it can realize the following effects, enable efficient data transfer, and minimize damage to the magnetic tape.

[Brief explanation of drawings]

FIG. 1 is a functional block diagram showing a first embodiment of the present invention;
Figure 2 shows the frame format, Figure 3 shows the frame format.
FIG. 4 is a diagram showing the data format within the group of the first embodiment. FIG. 5 is an explanatory diagram of the subcode pack of the first embodiment.
Fig. 6 is a recording processing flowchart of the data formatter of the first embodiment, Fig. 7 is a format diagram of groups recorded by the first embodiment, and Fig. 8 is reproduction of the data format of the first embodiment. Processing flowchart, FIG. 9 is a functional block diagram showing the second embodiment of the present invention, FIG.
The figure is an explanatory diagram of the pack of the second embodiment, and FIG. 11 is a flowchart of the recording process of the data formatter of the second embodiment.
FIG. 12 is a diagram showing the group format recorded by the second embodiment, FIG. 13 is a playback processing flowchart of the second embodiment, and FIG. 14 is a functional block diagram of the third embodiment of the present invention. Fig. 15 is an explanatory diagram of the pack of the third embodiment, Fig. 16 is a flowchart of the data formatter recording process of the third embodiment, and Fig. 17 is a diagram showing the data format recorded by the third embodiment. , Figure 18 is the third
2 is a reproduction processing flowchart showing an embodiment of the present invention. 1... Interface, 2... Command analysis issuing unit, 3... Command control unit, 4... Mechanical control unit, 5
...Data formatter, 6.. Extension storage section, 7.. Recording/playback section, 8.. Cylinder, 9..
...Rotary head, 10...Magnetic tape, 11.
...Buffer memory, 20...Second data formatter, 30...-Third data formatter.

Claims (3)

[Claims] (1) A magnetic device that has a rotating head and forms two inclined tracks constituting one frame on a magnetic tape by one rotation of the rotating head, and encodes digital signals on the inclined tracks and records and reproduces them. an interface for transferring data between the recording and reproducing device and the computer;
To perform recording and playback according to instructions from the computer,
This is a control method for a magnetic recording/reproducing device that is equipped with at least a command analysis/issuance unit that analyzes these instructions. A control method for a magnetic recording/reproducing apparatus, characterized in that recording is performed on a tape, and upon reproduction, the meaningless frames are omitted and the data of the frame in which the data is recorded is transferred to a computer via the interface. (2) The frame is configured to record and reproduce at least one frame of data at a time, and a continuous number indicating the number of the frame is recorded in the second recording area of the frame. This is a control method for a magnetic recording/reproducing apparatus configured in which a meaningless frame is added before or after a frame in which data is recorded, or both, according to instructions from a computer, and the second meaningless frame is Number the recording area consecutively with the number assigned to the frame in which data will be recorded.
2. A control system for a magnetic recording and reproducing apparatus according to claim 1, wherein frames in which data is recorded and frames having no meaning are distinguished from frames based on said number. (3) A flag indicating that the frame is not a frame in which data is recorded is recorded in the second recording area of a meaningless frame that is added to the frame in which data is recorded, and data is recorded with reference to the flag. 2. A control method for a magnetic recording and reproducing apparatus according to claim 1, wherein the control method is adapted to identify a frame.